CHALK-HILL BLUE BUTTERFLY. 235 



responding to the markings of the superior wings : 

 fringe white, spotted with brown. 



As this insect appears to have been found only 

 once in this country, and is not figured by any Bri- 

 tish author, we have been obliged in this instance to 

 deviate from our usual practice, and introduce a fi- 

 gure taken from a foreign specimen. It does not 

 entirely correspond to Mr Stephens's description of 

 the supposed indigenous example discovered by Mr 

 Jones in Buckinghamshire ; and should the latter be 

 found, as has been conjectured, to be only a variety 

 of P. Avion, we must exclude the present species 

 from our native catalogues. 



CHALK-HILL BLUE BUTTERFLY. 



Polyommatus Corydon. 



PLATE XXXII. Fig. 3. 



Pap. Corydon, Donovan, vii. pi. 131. f. 1. <$ .—Stephens 

 Illus. i. W.—Lewin, pi. 36 The Chalk-Hill Blue But- 

 terfly, Harris. 



One of the larger species, generally measuring 

 17 or 18 lines across the wings. The surface of 

 the male is a very light silvery blue, with a fine silky 

 lustre, the hinder margin of all the wings having a 

 blackish band, surmounted in the hinder pair by a 

 series of dusky, somewhat ocellated spots : the sur- 



